If the light is on you need to get the codes read and go from there.

Get yourself VCDS it's well worth getting, even the free version so you can check stuff yourself.

MAF sensors, coil packs, air leaks from PCV system are all common faults on them.

http://www.ross-tech.com/

http://www.ross-tech.com/vcds-lite/download/index.html - free download, for cheap cables (eBay) can do basic code reads and live data.

(limited measuring blocks)

Cable - http://www.ebay.co.uk/itm/VAG-GROUP-...item3f1b0d351a

If you have the free version and it works on your car you can pay a $99 dollar license fee to unlock more features etc.

If the oil light is because of the level sensor, check the fuses, these can sometimes blow causing the fault.